Answer:
B. as a food preservative in the manufacture of detergents
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The correct answer is - A) The major constituents of air are gaseous elements.
With the statement ''the major constituents of air are gaseous elements'' we can easily conclude that the air is a mixture. The reason for that is that we have a plural usage of the word element, elements, which mean that there are multiple elements that make up the air.
The air is indeed predominantly a mixture of gaseous elements. The most abundant gas in the air being the nitrogen with 78.9%, oxygen with 20.95%, argon 0.93%, and carbon dioxide 0.04%, with lesser amounts of other gases also be present in it. The water vapor is also present in the air, though it is variable, being around 1% at sea level, but only 0.4% over the entire atmosphere.
# moles = mass (g) / Mr (relative atomic mass)
# moles = 458 / ((23*2)+32+(16*4)
# moles= 458 / 142 = 3.2253521126760...
= 3.23 moles
% error = 3.4 %
Percent error = |accepted value - experimental value|/accepted value × 100%
∴ % error = |355 mL – 343 mL|/355 mL × 100 % = |12|/355 × 100 % = 3.4 %
